If your trucks break down, your fleet stops moving. And every minute of your trucks not being on the road means money lost! More often than not, electrical failures are the culprit behind truck breakdowns, especially in commercial vehicles where automotive wiring harnesses endure extreme temperatures, constant vibration and exposure to moisture, salt and road debris over hundreds of thousands of miles.
Finding the right truck wiring harness manufacturer is about finding a partner who understands the demanding environment of commercial trucking, can deliver reliable products that meet DOT standards, and has the technical expertise to solve complex electrical integration challenges—including custom wiring harness for semi truck applications.
Here are the top 9 truck wiring harness manufacturers based on their industry certifications, durability testing standards, and proven track record with major fleet operators. Cloom Tech stands out for their custom wiring harness offering, competitive pricing and fast delivery times, but each wiring harness company offers distinct advantages for different trucking applications.
How We Chose These Truck Wiring Harness Manufacturers
To pick the top truck wiring harness manufacturers, we applied criteria that reflect the demanding requirements of heavy-duty vehicle applications:
- Industry Certifications & Standards: We prioritized companies holding IATF 16949:2016 and ISO 9001:2015 quality certifications, backed by compliance with IPC/WHMA-A-620 workmanship standards.
- Truck-Specific Manufacturing Capabilities: Extra consideration was given to manufacturers with proven ability to produce heavy-gauge harnesses (2 to 4/0 AWG), multi-circuit systems and high-current load designs. We also looked for specialization in tractor wiring harnesses, tractor/trailer connectors, powertrain harnesses and body control module wiring.
- Environmental Testing: Truck harnesses face extreme operating environments, so we chose manufacturers conducting temperature cycling (-40°C to 125°C), SAE J1455 vibration tests, IP67+ sealing, along with resistance testing for salt, chemicals and abrasion.
- Production Scale & Capacity: Companies with dedicated truck harness lines, automated test benches and facilities capable of both rapid prototyping and high-volume OEM supply were prioritized.
- Quality Control Systems: We looked for advanced quality frameworks like PPAP, APQP and FMEA, along with full traceability through material batch tracking, production recordkeeping and archived test data.
- Industry Experience & Service: Finally, we considered proven history in the truck industry, with both OEM and aftermarket service experience. Strong engineering support, on-site technical assistance and after-sales service were also important factors.
Top 9 Truck Wiring Harness Manufacturers
1. Cloom Tech
Cloom Tech focuses on build-to-print truck wiring harnesses. Their biggest strength lies in their rapid manufacturing ability, offering 3-week prototyping and 4 to 5-week mass production, which makes them highly competitive for fast-moving truck development cycles.
With certified automotive-grade quality systems, they support quickly scalable production without compromising on traceability or compliance. Their facilities in China, the Philippines, and the US mean they can accommodate a range of project sizes.
Cloom Tech maintains strong supplier relationships with companies such as Mouser, Molex, and TE Connectivity, and has supported high-level truck and industrial programs for brands including Honda, Honeywell, and Geely—demonstrating proven expertise in semi truck wiring harness manufacturing and complex vehicle electrical systems.
| Pros | Cons |
|---|---|
| ✅ Supports up to 2 AWG conductor sizes, suitable for high-current truck systems such as starter cables, chassis power distribution and EV battery lines. | ❌ Most case studies focus on general automotive, smart home controllers and robotics rather than specific truck applications. |
| ✅ Can produce up to 10,000 pieces per hour depending on complexity. | |
| ✅ Equipped with Komax Alpha automatic crimping and wire processing machines, enabling precision terminations with pull-force validation and crimp-height control. |
Key Specs
| Company Started: | Founded in 2016 |
|---|---|
| Factory Information: | China, Philippines, USA presence. |
| Certifications: |
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2. Fortop Wiring Harness
Fortop positions themselves specifically as an OEM/ODM truck harness manufacturer, with dedicated pages for truck looms and pigtail harnesses. They also do both traditional 12V/24V systems and electric vehicle harnesses.
Their design scope covers 2 AWG to 26 AWG, enabling both signal and power distribution harnesses across light and heavy vehicles. They integrate over 18 quality control tests throughout production to ensure compliance.
Fortop is also focused on green manufacturing initiatives, like being certified for carbon accounting and sustainability. If you’re looking to work with companies putting effort into sustainability, they stand out in the industry.
| Pros | Cons |
|---|---|
| ✅ Can handle up to 2000 A in electric truck harness variants. | ❌ Taiwan-based operations might limit their ability to serve major truck manufacturers requiring global or nearshore manufacturing presence. |
| ✅ Implements version-controlled BOM & traceability system (RapidHarness) to ensure consistent build-to-build integrity. | |
| ✅ 18+ quality checkpoints, including reliability testing, gating inspection and process audits. |
Key Specs
| Company Started: | 1994 |
|---|---|
| Factory Information: | 3 factories in Tainan, Taiwan. |
| Certifications: |
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3. Julian Electric Inc
Julian Electric has a history in battery and power cable manufacturing, which gives them a high level of understanding when it comes to creating truck wire harnesses. They’ve partnered with well-known vehicle companies in the past, including Freightliner, Paccar, Mack, Volvo-White and more.
Though their historical strength lies in heavy-gauge and battery cable systems, they now integrate wiring harnesses across truck and vehicle platforms, especially where high-current paths and power distribution are involved.
| Pros | Cons |
|---|---|
| ✅ Supports wiring from 20 AWG to 4/0 battery cable, enabling both signal and high-current paths in the same harness. | ❌ While they manufacture wiring harnesses, their historical strength and major partnerships appear to center more on battery and power cables. |
| ✅ Uses custom test fixtures and formboards for 100% inspection of harnesses, enhancing test coverage and traceability. |
Key Specs
| Company Started: | 1959 |
|---|---|
| Factory Information: | 195,000 square-foot HQ in Lockport, Illinois; 90,000 square-foot factory in Saltillo, Coahuila, Mexico. |
| Certifications: |
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4. Carr Manufacturing Inc
Carr Manufacturing (CMC) makes wiring harnesses specifically for extreme temperature zones in trucks (around exhaust systems, heater circuits and powertrain enclosures,for example) where harnesses must be able to handle things like thermal spikes, vibration and shock.
They focus on reliability in demanding under‑hood conditions, leveraging materials, insulation and routing strategies suited for sustained heat and mechanical stress.
They also offer integration of sensor leads, multi‑branch distribution junctions and robust shielding in these circuits. CMC handles custom assemblies and full box-build support (eg. wire harness plus enclosures) for transportation and industrial use.
| Pros | Cons |
|---|---|
| ✅ Designed to withstand temperatures up to 200°C and high levels of shock and vibration. | ❌ With only 12 employees, they may have limited capacity compared to larger truck wiring harness manufacturers. |
| ✅ Incorporates vibration‑resistant routing and reinforced strain reliefs to maintain integrity under constant motion. |
Key Specs
| Company Started: | 2006 |
|---|---|
| Factory Information: | Foothill Ranch, California; facilities in Mexico and Asia. |
| Certifications: |
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5. WellPCB
WellPCB might technically be a PCB manufacturer, but they have plenty of experience in fabricating truck wiring harnesses to the same standard they make their circuit boards. Their wire harness division supports both low- and high-volume builds for truck applications like cab interfaces, trailer lighting, powertrain control and auxiliary systems.
One of their biggest advantages is accessibility: engineers can test concepts early with no MOQ, and easily ramp up to 10,000+ units when ready. WellPCB’s global production footprint allows for impressively short lead times across OEM and aftermarket programs.
| Pros | Cons |
|---|---|
| ✅ No MOQ, making them accessible for both large manufacturers and smaller aftermarket suppliers. | ❌ Mainly a PCB manufacturer that also offers wire harness services, which means truck wiring harnesses are a secondary offering rather than a specialization. |
| ✅ In-house continuity, insulation resistance, and terminal pull testing, aligned with IPC/WHMA-A-620 Class 3 for harsh-use vehicles. | |
| ✅ Supports complex multi-leg looms, including power-ground-routing integration for trailer, engine bay, and dashboard harnessing. |
Key Specs
| Company Started: | 2007 |
|---|---|
| Factory Information: | Wire harness facilities in Shijiazhuang, Shenzhen, Bangkok and Manila. |
| Certifications: |
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6. Cypress Industries
Cypress builds truck and trailer harnesses across multiple global sites, which helps to balance cost with easy access and regional after-sales support. As a truck wiring harness manufacturer, their truck & trailer harness line is built to handle the harsh environmental stresses that trucks encounter in real-world road operation.
They also offer custom braiding, potting and overmolding of harness segments or connectors to improve durability and environmental sealing. Cypress runs all facilities to common protocols and ERP systems, allowing them to offer consistent process documentation, design-for-manufacturability (DFM) and a high level of repeatability.
| Pros | Cons |
|---|---|
| ✅ RRugged braided harness designs with potting/overmolding in critical segments to bolster moisture, abrasion, and strain protection. | ❌ Their wide array of industries served indicates that truck wiring harnesses aren’t their main focus. |
| ✅ Support for MIL-spec wiring standards and military wiring protocols like MIL‑STD‑1460, MIL‑S‑45743, MIL‑STD‑2000 in addition to commercial harness lines. |
Key Specs
| Company Started: | 2001 |
|---|---|
| Factory Information: | Facilities in Dallas, Texas; Austin, Texas; Matamoros, Mexico; Changodhar, India; Dongguan City, China. |
| Certifications: |
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7. Precision Cable Assemblies
Although truck harnesses aren’t their primary focus, PCA features impressive truck and semi-trailer case studies, showing OEM-level delivery and organization for high-power wire harnesses.
PCA supports heavy-duty vehicle wiring needs with gauge ranges from 20 AWG to 4/0 and integrates features like injection-molded junctions, overmolding and sealed connectors to meet durability requirements in trucking and trailer systems.
Their process includes 100 % continuity testing, visual inspection for correct component placement and harness coverings like woven nylon braid, high-performance tubing, PET sleeving and heat-wrap tape to protect against abrasion, UV and chemicals.
| Pros | Cons |
|---|---|
| ✅ Builds from 1 circuit to >300 circuits with organized bundling and signal/power segregation. | ❌ Trucks aren’t their primary specialization. |
| ✅ Uses multi-material covering systems (eg. nylon braid, high-temp tubing, PET sleeve) rated up to 150 °C for protection in harsh truck environments. |
Key Specs
| Company Started: | 1980 |
|---|---|
| Factory Information: | Brookfield, Wisconsin; Waukesha, Wisconsin; Monterrey, Mexico; QingDao City, China. |
| Certifications: |
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8. Kinkong Wire Harness
Kinkong specializes in heavy-duty vehicle wire harnesses (although they do have a vast aftermarket portfolio) and stocks a large inventory of connectors which helps speed up delivery. Their product catalog explicitly includes “Heavy Duty Vehicle Wire Harness” alongside engine, relay, sensor and overmolded harness lines for trucks.
They provide both manual and semi-automated operations, with full assembly testing in-house. Kinkong also has a molding and tooling workshop in-house, which allows them to rapidly prototype new connectors or junction designs without outsourcing.
| Pros | Cons |
|---|---|
| ✅ Keeps 8,000+ connectors and terminals in stock across brands like Deutsch, Yazaki, Sumitomo, Tyco, Bosch, FCI, Molex, KET, significantly reducing sourcing delays. | ❌ Dedicated to aftermarket automotive industry, which may limit their suitability for major truck OEM manufacturers requiring dedicated OEM supply chains. |
| ✅ Operates internal mold/tooling and 3D prototyping capability, enabling rapid iteration of custom junctions or housings. | |
| ✅ Produces harnesses with 100% testing of every assembly, including continuity and insulation checks, to ensure quality before shipment. |
Key Specs
| Company Started: | 2010 to 2014 (unclear) |
|---|---|
| Factory Information: | Wenzhou, Zhejiang Province, China |
| Certifications: |
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9. Purkeys
Purkeys builds custom truck wiring harnesses to match each client’s specific needs. They’ve worked with some of the biggest names in trucking, like P.A.M. Transportation Services, Interstate Distributor Company, Southeastern Freight Lines and Maverick Transportation.
Not only have they got the backing of pro brands like those above, but they’ve also received glowing public recommendations from brands like Eaton and received awards (like the Corporate Engagement Achievement Award from the Technology Maintenance Council).
Something that makes them really different from others is that they offer electrical and multimeter training via webinars. They’re much more than simply a truck wiring harness manufacturer, but if you’re just looking for quality wire harnesses, their impressive background should give you peace of mind that you’re getting excellent products.
| Pros | Cons |
|---|---|
| ✅ Uses GXL Wire from Prestolite Wire for the safest possible application (installation will not reflow). | ❌ Specializes more in battery solutions for the heavy-duty trucking industry, indicating that wire harnesses are a secondary product line. |
| ✅ Designs custom trailer and tractor harnesses to support dual-voltage, multi-battery and shore power integration, often used in no-idle compliance systems. | |
| ✅Implements modular diagnostic connectors for real-time voltage monitoring and field troubleshooting, reducing service downtime in fleet applications. |
Key Specs
| Company Started: | 1990 |
|---|---|
| Factory Information: | Lowell, Arkansas. |
| Certifications: | Unclear. |
Final Thoughts
Picking a truck wiring harness manufacturer comes down to which one is the best fit. Match your wiring needs to a supplier with the right certifications, materials, testing depth and footprint for your heavy-duty or commercial vehicle build.
Shortlist the ones you like and run a prototype test with your drawings. Lock in PPAP, APQP, and service terms before scale. The right choice in this wiring harness market saves time, cuts rework and keeps your trucks on the road.
Grab a free quote from Cloom Tech in the meantime. No obligation, just an industry insight into how we can take your project from where it is now to full completion.
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